Process of cleaning soda.



UNITED STATES PATENT OFFICE.

DANIEL W. GILL, OF CHEYENNE, WYOMING.

PROCESS OF CLEANING SODA.

SPECIFICATION forming part Of Letters Patent No. 725,553 dated April 14, 1903. Application filed October 27, 1902. Serial No. 129,045. (No specimens.)

To all whom it WW/(by concern:

Be it known that I, DANIEL W. GILL, a citizen of the United States,residing at Cheyenne, in the county ofLaramie and State of Wyoming,have invented a new and useful Process of Cleaning Soda, of which/the following is a specification.

Myinvention is a process of cleaning naturalsoda; and the object of the process is to rid the soda of foreign matter and render it suitable for the manufacture of clear plateglass or for other uses for which a pure soda is required.

Heretofore the use of such natural soda as is found in the western part of the United States has been restricted to usein glass manufacture to the inferior grades, as the foreign matter contained in the soda interfered with the production of a clear glass and soda-ash has been used in the manufacture of the finest quality of plate-glass.

While my process is applicable to all natu-.

ral soda, yet the especial soda used by me in my process is shown by analysis to be as follows: sodium sulfate, (Na SO 9 1.50; magnesium sulfate, (Mgso 2.52; sodium chlorid, (NaOL,) 0.54; Water, 1.61; undetermined and loss, 0.83; total, one hundred. The soda thus found is in the form of crystals, which are soluble in water and will become pulverized on continued exposure to air.

My process is as follows: The soda is dissolved in warm water and allowed to stand until the foreign matter contained in the soda has fallen to the bottom or risen to the surface, according to its specific gravity. That which rises to the surface is then drained or skimmed off, and the soda in solution is then cooled to a temperature above the freezingpoint, when the soda will recrystallize and The Will be found free from foreign matter.

water and soda crystals are then separated in any desired manner.

Careful experimentation shows that the best results are obtained by heating the water to a temperature of 160 Fahrenheit and then permittingthe temperature to fall to about 140, and I retain this temperature un til the foreign matter has separated from the soda. I then draw the solution off into anperature of about 50 Fahrenheit.

The soda will dissolve some and recrystah lize some at other temperatures; but better results financially are secured by having the temperature as above.

An analysis of the cleaned sodahas shown the following: sodium chlorid,0.0S; sodium sulfate, 99.92; water, none; total, one hundred. An analysis of this soda before cleauing has already been given.

Having thus fully described my invention,

DANIEL W. GILL.

Witnesses:

WILL J. ELLIOTT, G. E. MoGARvEY.

.5 other vat and recrystallize the soda at a tem- 

